Actors Megan Mullally and Nick Offerman, who put their house in the Hollywood Hills West up for sale this week at $12.65 million, might want to send a thank you card to the new neighbors for the great "comp."

Last month, 31-year-old twins Tyler and CameronWinklevoss — who won a $65-million cash-and-stock settlement in 2008 over claims that Mark Zuckerberg stole their idea to create Facebook — bought the contemporary house next door for $18 million.

The newly constructed two-story has retractable walls of glass opening to views of downtown L.A. and an infinity swimming pool with a shallow-water shelf for chaise longues. A living room wall of sleek stone containing an extra long fireplace and spots for flowers bears some resemblance to a mausoleum wall. Counter seating for five sits off the sleek white kitchen. A waterfall fountain creates a backdrop for a spot of lawn, and a metal sculpture provides a focal point for a reflecting pool on the third-of-an-acre lot.

The acting couple, both of whom have appeared on "Parks and Recreation," aren't going to be around to get to know the twins, however. They already have another house in hand.

Purchased at the end of last year for $4.15 million, their new place in Bel-Air is described as having museum-quality finishes, soaring ceilings and high-end details. The nearly 5,200-square-foot contemporary features a flexible floor plan, four bedrooms and 31/2 bathrooms on one floor. There is a solar-heated swimming pool on the nearly half-acre canyon-view lot.

Michelle Nelson of Sotheby's Sunset office had the listing on the house Mullally and Offerman bought. Rory Barish of Keller Williams in Beverly Hills represented them in the purchase.